I think typically you get them from rental companies that rent tents, chair covers, etc. Party Decor in North Royalton came up as one company that has it if you search "ceiling drapery cleveland ohio" and they have chair covers for $2.95 (on their ad on weddingsincleveland.com) which is pretty reasonable. They also have kits on eventdecordirect.com. No idea if that's a good option/price or something that's easy to do yourself.
Re: Draped ceilings